Baking apparatus



BAmG APPARATUS Stanley H. Rayner, Salisbury, Md.

Application January 7, 1955, Serial No. 4%,479

10 Claims. (Cl. lili/' This invention relates to baking apparatus, and more particularly to ovens of the type used in bakeries for baking products in large quantities.

ln the baking of certain products, such as pullman or sandwich loaves of bread, it is desirable to cover the baking pans containing the dough, or other material to be baked, during at least a portion of the baking period. When the baking pans are covered, several advantages are realized. Over-coloring of the rst material loaded in the empty oven is eliminated; the crust is more tender and uniform in color than the crusts produced by conventional methods; and the baked product itself has a soft feel.

ln spite of the improved results achieved by the use of pan covers, such covers have not been used in cornmercial baking as extensively as would seem to be indicated. This fact is, no doublt, the result of the increased diiculty and expense which has accompanied the use of pan covers.

The system in use prior to the present invention required the oven attendant to place pan covers on each strap of baking pans prior to the insertion of the pans into the oven, and to remove the covers from the pans as they were removed from the oven so that the bread or other baked product might be dumped from the pans. These cover handling operations consumed substantial amounts of time, with a corresponding reduction in the potential capacity of the oven. Furthermore, the handling of the hot pan covers posed a significant safety problem.

Aside from the difhculties involved in handling the pan l covers of the prior art, the system proved to be an expensive one from the standpoint of equipment maintenance. The pan covers had to be replaced at frequent intervals due to the bending and abuse thereof, which occurred during the application and removal of the covers from the baking pans.

This invention overcomes the diliculties associated with the prior art system of baking in covered pans by permanently attaching pan covers to the conveyer means of the oven in such a way that the pan covers may be raised and lowered in respect to the conveyer means. conveyor means approaches the pan loading station, the pan cover is caused to assume its elevated position so that the baking pans may be positioned upon the conveyor means below the pan covers. Then, as the conveyer means moves on, past the loading station, the cover is lowered so as to rest upon the top edges of the baking pans.

The pan cover of this invention is substantially flat. With a cover of this conguration, the sides of the baking pans remain exposed to the hot atmosphere of the oven so that proper heating for uniform baking is assured.

Although the pan covers of this invention may be applied to any of the commercial ovens now in use, their use is particularly advantageous in ovens of the tray type. ln this type of oven, a plurality of trays are suspended from an endless conveyer, and a number of baking pans are supported upon each, of the trays, As the conveyor As the moves, the trays are carried through the baking zone of the oven. After the baking has been completed, the pans containing the baked product are removed from the trays, and other pans are loaded onto the trays. One of the pan covers of the present invention is movably mounted upon each of the trays so that it may assume a covering relationship with respect to the pans carried by the tray, without regard to the path of travel of the tray. The signicance of this feature will be apparent when one considers the devious courses followed by the trays in some commercial ovens.

Each of the pan covers is attached to its tray by parallel links so that the lower surface of the pan cover will always remain parallel with the upper surface of the tray. This permits the handling of pans of different heights in the equipment, the only requirement being that all of the pans on a given tray be of the same height.

The raising and lowering of the pan covers is brought about by stationary cams xed to the walls of the ovens. rFliese cams are so located as to control cam followers carried by the pan covers as the conveyer moves along through the oven. There may be as many of these cams as necessary, and the cams may be located at such positions in the oven as to satisfy the varying requirements of the production or the demands of the baker. Also, the cam for lowering the pan covers may be mounted so that it may be moved to an inoperative position from the outside of the oven, when desired. Thus, it is possible to carry out the entire baking operation with the pans in the uncovered condition.

A better understanding of this invention and its many features and advantages will be gained from a consideration of the following detailed description of an embodiment thereof, illustrated in the accompanying drawings in which:

Fig. l is a somewhat diagrammatic longitudinal crosssectional View of a single-lap, tray type oven;

Fig. 2 is an enlarged vertical cross-sectional View, along the line 2 2 in Fig. l;

Fig. 3 is an enlarged vertical cross-sectional View, along the line 3 3 in Fig. 1;

Fig. 4 is a detail View approximately along the line 4 4 in Fig. l, showing the pan cover lowering cam;

Pig. 5 is a detail view approximately along the line 5 5 in Fig. l, showing the pan cover raising cam; and

Fig. 6 is a detail vertical cross sectional view showing the mechanism for rendering the pan cover lowering cam of Fig. 4 inoperative when desired.

It will be evident to persons skilled in the art that the illustration of a particular type of oven in Fig. l of the drawings is by way of example only. The principle of this invention may be applied to tunnel ovens, reel ovens, double-lap ovens, etc., as Well as to the single-lap oven illustrated in Fig. 1. Additionally, it is pointed out that the showing of Fig. l is largely schematic. Many of the structural features of the oven have been omitted from the illustration in the interest of clarity. These features have no direct bearing upon the present invention and they are well known in the art.

The oven walls are indicated generally by the numeral 2. These walls are of insulating material, as is conventional in the art. The front wall 4 of the oven is interrupted by an opening 6 through Which the oven may be loaded and unloaded. In many ovens, sliding doors are provided for closing the opening 6 when desired. Also,

in many ovens, a separate discharge opening is provided in one of the Side walls. Since the present invention is not dependent in any way upon these features, they have been omitted from Fig. l.

Disposed within the oven are a plurality of sprocket wheels 8, rotatably mounted upon shafts 10. A set of four of the sprocket wheels 8 is located close to each of the side walls of the oven, with the sprocket wheels 8 of each set being arranged in the pattern illustrated in.

Fig. 1. VCarried by the sprocket wheels 8 of each set, is an endless conveyer chain 12. One ofthe. shafts 10 is driven by V,suitable power means to cause the chains 12 to move in the paths dened by the sets of sprocket vwheels and in the'direction indicated by the arrow in Fig. l.

l Pivotally suspended between'. the chains 12 by rneansof sub shafts 14 and tray hangers 16 are a number of trays I8. The traysV 18 are relatively heavy so that their upper surfaces will remain in a horizontal position throughout their paths of travel on the chainsl 12. In the drawings, the upper surfaces of the trays 18 are flat. Y' However, as is well understood in this art, the surfaces may be ribbed` somewhat to Vspace the bottoms of the. baking pans 20 slightly above portions' of the.V upper surfaces of the trays to facilitate heat transfer.. Y

VlrIhe4 baking pans 20have been omitted from Eig; l, because of. thev small scale of this: view; The relationshipA of the pans 2()` withl respect to. the other elements will be clear from a considerationv of Figs. 2. andv3.

1 lYI-ountedfr'uponV the `front and back surfaces of each of the traysV 18 are upstanding bracketmembers 22. These brackets carry pivots 24.v at their upper ends, and parallel linksY 26 are attached tov the. pivots. Thev upper ends of Vthe parallel links 26 are pivotally connected to depend- Y tion is assumed at some point in the path. of. travel of lthe tray 18 beyond the zone in which Vthe pans -20 are loaded onto it, as willrbe evident 'from Fig. 1. The. particular position inwhichV theY lowering of the cover. is brought about can be determined to suit the particular requirements of the baking operation being carried out.

As will be described 'hereinaften the' means for. lowering` the Vparl covers operatesV automatically sor-that it may be inaccessible to the oven attendant withoutin any' way interfering with ,its operation. i l

.In Fig. 3, the cover 39 is showninits raised. position with respect to the baking; pans 20.*. In this position, theY links 26 bear against theflower edges ofV the brackets Y 28,'to` preventl the cover from swinging. too'farA toftheV left, as. viewed in Fig. 3-. VThe position illustrated is a stable-one so that no speciall means needbe providedffor holding the cover in this position.

As in the case ofthe lowering'of the pan cover 3.0

Y into the position shown inFig. 2, the: raising of the pan cover into the Vposition shown in Fig;v 3f may take place at any desired point in the path of travel of theY trays 18 through the oven.

which are not accessible to the attendant.

Again,. theY operating means: is'y entirely automatic sovthat it may be located` in'positions Yaccompanied by a lowering ofthe cover 30 into the 'position shown in Fig. 2.

The cam track 42 is iixed to links 44 and 46, pivotally connected at 48 and 50 to upstanding brackets attached Vto a guide track 54. The guide track 54 is attached by means of bolts 56 or other suitable means to a sidewall 58 of the oven.

The links 44 and 46 normally rest upon therupper edge of the guide track 54 to maintain the cam lowering track 42 in its operative position. However, these links may swing about the pivots 48 and. 50Y so as to lift the cam track V42 out of the path of the cam follower 38. In some circumstances it may be desired' to lift the cam track out of its operative position so that the baking may proceed with the pan covers in the'raised position. This may be accomplished by depressingY the outer'end of. one of the links. 44 by pulling on a chain or other connecting member 60', attached. tothe link and extending downwardly through a hole. 59 in; the bottom ofthe oven 2. As shown in Fi'g. 6g thetlower endl of" the chain 60 may be connected' to an actuatinglever 61 Y pivotally mounted on the exterior of the oven 2..

Additionally, the raising. of. the cam track 42 may take place automatically.

track. 42. until it drops below the lower edge of such surface. The parts are dimensioned so that the cam follower 38 Ymoves out of engagement withthe surface ofthe cam track 42 just as. the lower surface of the pan cover 30 comes into covering relationship with respect to baking panse of minimum height. When tallerpans are employed, the cam'follower 38 will. still bein engagement.

with the cam track-42 when the cover 30 contacts the upper edges ofl the pans 20. In this situation,. further lateral movement of they cam. fol1ower'38 will not-take place. Instead, the cam track 42 will be raised,` swinging about the axis. of thepivots 48 and 50. This feature of the'invention permits the. handling of pans of diierent heights without makingvv alterations or adjustments-of the equipment,

The guide 54. prevents the. cam follower 38 from swinging'uncontrolledly to the right,.as viewed in Fig. 3. Unless 1 of the pan I8.V It is held in fixedA relationship with re- Y The upper surface of the pancover'Stl' carries a bracing Y Vrib 32 along its longitudinal center portion; The upper surface of the rib 32 is'horizontalfor most of Vits extent,

Vbut-is cut away at aslight angle near one of its ends'to provide an inclined surface Y 34;. Extending' fromv theV inclinedtsurface34 is-aspindle 3'6. upon which is.' rotatably mounted a camfollower or control'.` bearing.38. l i

The cam meansI for raising.v ther'pan cover. 30; is best illustrated in Fig. 4'ofthe drawings. ,Thez tray `18.*inv

Fig. -4 moves inthe direction indicated by' the. arrows Y applied toit. As the cam-follower 38, inthe raisedl Y positron of' Fig'. 3, moves.' along'rirrv the direction' of thefV spectto the tray- 18. lateralirnovementofthel cam about'the piovts 24. Y Y

spect to the side wall S8 of the oven by means'of bolts 64 or other suitable fastenings. As the camfollower 38 movesv alongv in the direction ofvtravel' of. the'tray 18, it willi contact the surface ofthel cam track 62 andv be moved laterally to the left from the positions. shown in Figs. 2` and '5. This lateral movement is accompanied by a raising of the cover 30' as. the parallellinks 26v swing It' should be notedthat Figs.. 4 and'Sfare taken on Vplanes parallel to the inclined' 4surface 34'of the cover brac'ingrib 32rather than on absolutely horizontal planes. The inclination ofthe .surface 34 is suchv as to dispose the. aXis of thecam follower 38 at agsrnall inclination withrrespect to the vertical; In this position, the. inclina#V tion of the" surface of thecam follower`38 islmaintainedt more nearly constant during ythe shiftingy movement of theA coverV 30., and more perfect cooperation .between the Y Y earn'follower and the camitrack's is achieved.

The operation roflt-he` apparatus' of` this invention now be1summarized'.l Y o Y Y l Y When the conveyer chains 12 are setf inY motion byV thev application of power toY one ofthe sprocket wheels Y Normally, the cam follower. 38 will remain in engagement with the inner surfaceI ofthe cam 8, the trays 18 travel along through the oven. As a tray passes the opening 6 in the front wall of the oven, it is loaded with bread pans 20. At this time, the cover 30 is in the raised position shown in Fig. 3.

As this tray moves on into the oven, the cam follower 38 attached to its pan cover 30 comes into contact with the cover lowering cam track 42, Fig. 4, and the cover is shifted downwardly and to the right. This brings the lower face of the cover into Contact relationship with the upper edges of the baking pans 20, as illustrated in Fig. 2.

At the end of the baking cycle, or at some time prior to the end of the cycle, the cam follower 38 comes into Contact with the cover raising cam track 62 illustrated in Fig. 5. This cam track causes the follower 38 and the attached pan cover 30 to be shifted upwardly and to the left from the position illustrated in Fig. 2 to the position illustrated in Fig. 3. The parts remain in these relative positions until the tray 18 again moves to that portion of the conveyer path adjacent the opening 6. Then the pans 20 containing the already baked products are removed from the tray 1'8, and new pans containing unbaked material are inserted.

While a single embodiment of this invention has been described in considerable detail, various modifications will be apparent to persons skilled in the art. AIt is intended, therefore, that the foregoing description should be considered as exemplary only, and that the scope of the invention should be determined from the following claims.

I claim:

l. In a bakery oven having a baking zone, means for heating said zone, and power driven conveyer means for conveying pans of material to be baked through said zone, the improvement which comprises a pan cover having a substantially flat lower surface adapted to rest upon the top edge of a pan of material to be baked while leaving the side walls of the pan substantially exposed to the heat of said baking zone, means for mounting said pan cover on said conveyer means for movement relative thereto in a direction having a vertical component, and stationary cam means `adjacent the path of said conveyer means for lowering and raising said pan cover into and out of covering relationship with respect toa pan of material carried by said conveyer means as said conveyer means moves relative to said cam means.

2. A bakery oven tray having an upper surface for supporting a baking pan containing material to ybe baked, a pan cover having a substantially tlat lower surface for resting upon the upper edge of the baking pan, and a plurality of parallel links pivotally connected near their lower ends to said tray and pivotally connected near their upper ends to said pan cover so as to permit raising and lowering of said cover relative to vsaid tray While maintaining the lower surface of said pan cover substantially parallel to the upper surface of said tray, whereby baking pans of different heights may be accommodated.

3. In a bakery oven having a heated baking zone `and conveyer means for conveying baking pans containing material to `be baked through said zone, the improvement which comprises a pan cover adapted to rest upon the top edges of a plurality of baking pans carried by said conveyer means, `a set of parallel links each of which is pivotally connected to said conveyer means and pivotally connected to said pan cover, and means for automatically swinging said pan cover on said parallel links into and out of covering relationship with respect to said baking pans.

4. yin a bakery oven having a heated baking zone and conveyer means for conveying baking pans containing material to be baked through said zone, the improvement which comprises a pan cover adapted to rest upon the top edges of a plurality of baking pans carried by said conveyer means, a set of parallel links each of which is pivotally connected to said conveyer means and pivotally connected to said pan cover, a cam follower attached to '5 and extending upwardly from said pan cover, a stationary cam track in the path yof movement of said cam follower for swinging said cover on said parallel links to raise it from covering relationship with respect to said 'baking pans.

5. VIn a bakery -oven having a heated baking zone and conveyer means for conveying baking pans containing material to be baked through said zone, the improvement which comprises a pan cover adapted to rest upon the top edges of a plurality of baking pans carried by said conveyer means, a set of parallel links each of which is pivotally connected to said conveyer mean-s and pivotally connected to said pan cover, a cam follower attached to and extending upwardly from said pan cover, a stationary cam track in the path of movement `of said cam follower for swinging said cover on said parallel links to lower it into covering relationship with respect to said baking pans.

6. In a -bakery oven having a heated baking zone and conveyer means including a generally horizontal portion for conveying `baking pans containing material to be baked through said zone, the improvement which comprises a pan cover having a generally horizontal lower face adapted to rest upon the top edges of a plurality of baking pans carried by said horizontal portion of said conveyer means, a set of parallel links each of which is pivotally connected to said conveyer means `and pivotally connected to said pan cover, a cam follower attached to the top of said pan cover and extending upwardly and outwardly from a side port-ion thereof lat an angle to the vertical, a cam track having a can face inclined yat about the same angle as said cam follower, and means for mounting said cam track on 'said oven, isaid `cam face being located in the path of movement of said `cam fol- 'lower and extending laterally at an angle with respect to such path so as to swing said cover on said parallel links as said cover moves past said cam track.

7. In a bakery oven having a heated baking zone and conveyer means for conveying baking pans containing material to be baked through said z-one, the improvement which comprises a pan cover adapted to rest upon the top edges of a plurality of baking pans carried by said conveyer means, a set of parallel links each of which is pivotally connected to said conveyer means and pivotally connected to said pan cover, a cam follower attached to and extending upwardly from said pan cover, a cam track, and means for mounting said cam track in said oven so that it will normally assume a position in the path of movement of said cam follower for swinging said pan cover on said parallel links but permitting it to move out of said path under the influence of said cam follower when said cover has reached the limit of its swinging movement.

8. ln a bakery oven having a heated baking zone and conveyer means for conveying baking pans containing material to be baked through said zone, the improvement which comprises a pan cover adapted to rest upon the top edges of a plurality of baking pans carried by said conveyer means, a set of parallel links each of which is pivotally connected to said conveyer means and pivotally connected to said pan cover, a cam follower attached to and extending upwardly from said pan cover, a coverlowering cam track, means for mounting said cam track in said oven so that it will normally assume a position in the path of movement of said cam follower for swinging said pan cover on said parallel links but permitting it to be moved out of said path, and means operable from the exterior of said oven for moving said cam track out of said path so that said cover will not be lowered onto the baking pans.

9. In a bakery oven having a baking zone adapted to be heated, an endless conveyer extending into said zone, and a plurality of trays suspended from said conveyer for carrying a plurality of baking pans containing material to be baked through said baking zone, the improvementtwhich VVconiprisesz a'pluralityof pan coversK each of.

which is adapted to. rest uponv the top. edges of thebaking. Y

pans carried by` one of Vsaid trays; while leavingY the. side Wallsv ofY said' pansV substantiall')F exposed to: thel heat of said'zone, a set of'parallel links movably mounting each of said pan covers on onei of said trays, the links of each of said sets being pivotally connected toy the trayV and pivotally connected to the pan. cover associated there'- with, rst means adjacent a Aiirst portion-of the path of said conveyer operating as each of said trays' movesi over said rst portion of Vthe path of the conveyer to move the pan cover mounted thereon into covering relationship with respect to the pans carried thereby, and secondi means adjacenta second portion of,` the path of said the top.v edges of ai plurality of barkingV pans carried' by saidconveyer' means means'V for mounting said pan cover for movement into andY ont of ,covering relationship with respect to said pans, a, cam follower attachedgtoY said panV cover, a cover-lowering cam track, means,` for'mounting said track in said oven so thatit will normally assume` a position inthe path of movement of said cam-fo1lower but permitting it tobe moved out of said path, and mea-ns operable toV move said cam track outV of saidfprath so that said cover willnot be lowered onto' the baking pans.

References Cited in thev le of this patent UNrrED STATES rrrENTsk 775,913' Dietz-; Nov.r29,l904

1,491,689 Gantvoort' Apr. 22, 1924 1,672,954 Pointon vJune 12, 1928 2,539,423 Howard Jan. 30, 19151v 2,648,298 Holbeck Aug. 11, 1953I FOREIGN YPATENTS 7,1173 Great Britain Nov. 12,V 1915 

